Which antidepressants can treat my Irritable Bowel symptoms?

You might be wondering why a doctor would prescribe an antidepressant to treat your irritable bowel syndrome (IBS). Sometimes low doses of antidepressants are prescribed for IBS, even if the IBS sufferer is not depressed. Research has shown that two main types of antidepressant (SSRIs and TCAs) help IBS symptoms. Antidepressants can reduce pain sensations and other symptoms in IBS sufferers.

Using antidepressants to treat IBS is what doctors and pharmacists call an ‘off-label’ use of the drug. Off-label means the medication is used in a way not specified by the FDA or Health Canada on the drug packaging label. Off-label medication use (which should only be prescribed by a doctor) is legal and common, and often supported by scientific studies.

Medical associations, such as the American College of Gastroenterology, have concluded that there is enough evidence to support the use of certain types of antidepressants to treat IBS symptoms.

How can antidepressants treat IBS symptoms? Don’t antidepressants normally work in the brain?

Traditionally, antidepressants are used to treat chemical imbalances in the brain. Antidepressants boost mood-related chemicals by targeting special cells called neurons. Different types of neurons have different functions. Some neurons, for example, secrete serotonin. Antidepressants that target serotonin neurons are called SSRIs. SSRIs (one of the most commonly prescribed type of antidepressant) boost serotonin levels. TCAs (another type of antidepressant) boost both serotonin and epinephrine levels.

So how does it make sense to use antidepressants to treat gut problems?

The gut and the brain are in constant communication. What happens in the gut affects the brain and vice versa. Getting butterflies in your stomach when you are anxious is one good example of your brain and gut talking to one another!

Like the brain, the gut also has neurons. The gut has so many neurons that it has been called our ‘second brain’. Some neurons in the gut produce serotonin, like the serotonin-producing neurons in the brain. In fact, the gut produces over 90% of the serotonin in the body.

Scientists speculate that the impact of antidepressants on the serotonin-producing gut neurons is the reason antidepressants can alleviate IBS symptoms. But more research is needed to fully understand how this works. The latest thinking is that because many IBS sufferers have issues with pain perception and antidepressants reduce our perception of pain, antidepressant treatment makes sense.

Long-term anxiety or depression has also been linked to gut disorders. It is not unusual for IBS sufferers to also have anxiety or depression. For that reason, a prescription of antidepressants meant to treat anxiety or depression is not uncommon for IBS sufferers.

Does the type of antidepressant make a difference?

The type of antidepressant used to treat IBS does matter. Studies show that depending on your main symptom (diarrhea, constipation, or a mix of both), some people respond better to certain types of antidepressant.

Tricyclic Antidepressants (TCAs)

TCAs have been shown to be better for diarrhea-predominant IBS (IBS-D). These drugs slow down gut motility, which helps reduce diarrhea. Unfortunately, TCAs can have side effects such as drowsiness, dry mouth, blurred vision, sexual problems, dizziness, tremors, headache, and weight gain. Some commonly prescribed TCAs aree:

Selective Serotonin Reuptake Inhibitors (SSRIs)

SSRIs have been found to be better for treating constipation-predominant IBS (IBS-C). Generally, fewer side effects are reported for SSRIs than TCAs. These include nausea, diarrhea, anxiety, headaches, loss of sex drive and weight-gain. Some commonly prescribed SSRIs are:

Can Pillcheck help me find an antidepressant to treat my IBS symptoms?

If you are considering antidepressant treatment, Pillcheck can help. Not everyone metabolizes antidepressants the same way. Based on your genetics, you may have a harder time processing some types of antidepressants. This can increase unpleasant side effects and make your treatment less effective. Pillcheck tests your response to many of the antidepressants used to treat IBS symptoms. Our team of specialized pharmacists review your test results and provide you with an opinion letter to help you and your doctor find the most effective treatment.

Share this post

Author

Andrea Huston, MSc – Andrea is passionate about communicating science and aims to translate scientific knowledge into information that is accessible and relevant to everyday lives. Andrea has a background in Molecular Biology and Genetics, having completed her Master of Science at the University of Toronto. She also completed a Professional Writing program and has since published works on a range of topics – including human genetics, behavioural science and drug therapies. Andrea currently works in the field of genomics and continues to write about the latest scientific discoveries.